Only valid for active forum users. Active means at least 30 postings within the last 30 days (no spam postings). This will automatically being checked at www.starbike.com shopping basket so make sure that you are logged in at the WW board!If there does not appear a WW discount position when you check out you do not have enough postings!

In my very rough race today (Copperopolis for you NorCal folk) my FD made some unwanted down shifts.

I have ridden some rough roads on this Red setup before but not as this level of roughness as its been on the bike less than a year.

I could have been accidentally bumping the lever with my hand. Or it could have been gravel hitting the exposed shifter cable on the down tube.Or there's something in the mechanism that causes unwanted downshifts when you hit sharp bumps.

I would just switch to the new Yaw derailleur (its what I did) and I had no issues at Copperopolis yesterday... With the exception of my headtube and stem nuts rattling free. Riding from the downhill segment to the finish line with free spinning stem (hand tightening it constantly while I rode) would have been funny if wasn't so terrifying.

I have the Yaw FD already. Not sure how a different derailleur would prevent it.

Riding that downhill with a loose stem would make it extra exciting... like the truck with cattle trailer coming up that we met on our first lap.When there's no other traffic on that road I kind of enjoy it.

Oops read the first line and that overrode what you wrote in the subject line. The only thing I can think of for rear shifting is make sure that there is no slack in the line and if you are not already running compression-less housing you should consider making the switch. Although that will just make the shifting better and has nothing to do with auto-shifting.

On that first climb, the guy in front my had his rear-derailleur detonate...I think Copperopolis is just bad for equipment. That truck-trailer was really hauling ass and the spray from the asphalt/gravel is what I think cut my finger, although honestly I didn't notice the cut till the 2nd loop.

My wife's bike does this occasionally with very hard efforts on her DA 7900 equipped Ruby. I actually got her to reproduce it in the trainer - the frame is flexing enough move the derailleur over and dropping the chain.

If your cable tension is too high, or your high limit screw is too far in, then the shifter may juuust barely be clicking into position for the big ring, allowing it to slip out of position when jostled.

It could also be that the shifter was just barely clicked into poisiton in the big ring because of me- I sometimes don't push it all the way. I discover that when the chain rubs the front derailleur cage in the small cogs. I think it's because I spent so much time on Shimano 7800 which has a much lighter action (and shorter lever throw for FD upshifts).